cfg80211: add channel tracking for AP and mesh

We need to know which channel is used by a running
AP and mesh for channel context accounting and
finding matching/active interface combination.

STA/IBSS have current_bss already which allows us
to check which channel a vif is tuned to.
Non-fixed channel IBSS can be handled with
additional changes.

Monitor mode is going to be handled differently.

Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index 1fc89c4..c62bc78 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -2408,6 +2408,9 @@
 	struct ieee80211_channel *preset_chan;
 	enum nl80211_channel_type preset_chantype;
 
+	/* for AP and mesh channel tracking */
+	struct ieee80211_channel *channel;
+
 	bool ps;
 	int ps_timeout;